X4000 in RYYR Led Condition (External Temperature)

Unit has been working fine since rebuilding about a week or so ago. Moved this X4000 into my office (with another one) and repowered it. The leds go into RYYR (The external temperature exceeds the normal limit. This may be due to anobstruction of airflow in front of or inback of the workstation.). Nothing is blocking the front or rear and I feel no considerable heat from the fans and the system is running fine. Even if I power it down for several hours and power on, it immediately goes into the RYYR condition so I suspect a bad sensor. Where exactly does the unit get the "External Temperature" measurement from? Is there a sensor integrated in the front panel? Or is this one of the mainboard sensors? Also, another clue, I have one X4000 running WinXP Pro and used speedfan to read the temp sensors, all reported properly. The unit with the errors is running Win2K3 and speedfan does not recognize any sensors (they all say zero degrees and fan speeds of zero). Not sure if this is a Win2K3 issue or a sensor problem.

Is it possible that there is a bad power supply? Other than the flashing front panel, the system is operating normally (unless it's on the verge of a meltdown and I just don't know it.)